Abstract: A pretreatment process is disclosed for increasing conversion and reducing the fouling rate of reforming catalysts wherein the catalyst is pretreated at a temperature from 1025.degree. F. to 1275.degree. F. in a reducing atmosphere prior to contacting the catalyst with a hydrocarbon feed in the presence of hydrogen.
Type:
Grant
Filed:
November 15, 1993
Date of Patent:
January 17, 1995
Assignee:
Chevron Research & Technology Co., a Div. of Chevron U.S.A. Inc.
Inventors:
Bernard F. Mulaskey, Robert L. Hise, Steven E. Trumbull, William J. Cannella, Robert A. Innes
Abstract: On-stream catalyst replacement apparatus for countercurrent upstream flow of a gas and hydrocarbon liquid through a downward moving catalyst bed in a reactor vessel. A mixed feed stream of gas and liquid hydrocarbon components enters a reservoir formed between the lower end of the reactor and a conical screen supporting the lower end of a catalyst bed. A wall across the vessel divides the reservoir into a lower surge chamber for receiving the mixed feed and an upper plenum chamber for separating the components into alternate feed rings of gas and hydrocarbon liquid under the conical screen. The mixed feed enters the plenum chamber through a plurality of tubes extending downwardly from the wall to the same depth in the surge chamber that prevents establishing preferential paths for gas to independently enter the plenum chamber.
Type:
Grant
Filed:
February 8, 1993
Date of Patent:
April 12, 1994
Assignee:
Chevron Research and Technology Co.
Inventors:
David C. Kramer, Bruce E. Stangeland, David S. Smith, James T. McCall, Georgieanna L. Scheuerman, Robert W. Bachtel
Abstract: An apparatus for simultaneously distributing catalyst particles across the full diameter of catalyst bed with a single rotor is disclosed. The bed has substantially uniform high density by forming a multiplicity of annular rings of catalyst concentric with the vessel or bed center. Such action is achieved without varying rotor speed by deflecting catalyst from a feed hopper into a plurality of arcuate sectors or portions of different radial lengths on a rotating disk-like member. Preferably, each arcuate portion has a volume proportional to one of the annular areas of the bed within the cross-sectional area of the vessel. The desired volume is formed by the radial length of the arcuate sector, its included angle on the disk, and the height of the vanes separating adjacent sectors.
Abstract: Disclosed herein is a process for preparing substantially pure crystalline SAPO-31 molecular sieve. In particular, disclosed are methods for preparing SAPO-31 which methods employ specified crystallization media with specified pHs. When such crystallization media are employed, the resulting SAPO-31 is substantially pure and has no contamination from crystalline SAPO-11 silicoaluminophosphate molecular sieve.
Abstract: A double hull vessel is disclosed having a novel type of ballast tank element. That ballast tank element has a half-breadth double-bottom ballast tank and a side ballast tank. The half-breadth double-bottom ballast tank has a tank access trunk that is located within the double-side hull. Preferably, that tank access trunk is at least one frame space wide. The side ballast tank is located within the double-hull, and is adjacent to the tank access trunk. Preferably, the ballast tank elements are used in pairs which are adjacent and opposite from each other. These pairs of ballast tank elements can be used in conjunction with double-hull ballast tank elements having no internal subdivisions.
Abstract: The present invention is a process to recover metals from refractory ores. It involves the chlorination of an ore concentrate in the presence of solid salt at a temperature between 300.degree. and 650.degree. C. Thereafter, an oxidation step can be used to convert iron chloride to iron oxide. Subsequent separation steps remove the salt, gangue, and iron oxides. Separate pathways are described for precious and base metal recovery.
Abstract: A process is disclosed to extract cobalt and optionally, at least one metal value selected from the group consisting of molybdenum, nickel, tungsten, and vanadium from metal-containing particles, such as spent hydroprocessing catalysts particles containing carbon residue. In this process, the spent catalyst particles are roasted in an oxygen-containing gas at a temperature of from 400.degree. C. to 600.degree. C., and then the roasted catalyst particles are contacted with an aqueous solution of ammonia, ammonium salt, and hydrogen peroxide. The aqueous solution has an initial pH of at least 9.5 and an initial hydrogen peroxide concentration of from 0.02 to 0.2 M. That aqueous solution is maintained at a pH of greater than 9.5.